<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>v-model</title>
</head>

<body>
    <div id="app">
        姓:<input type="text" v-model="firstName">
        名:<input type="text" v-model="lastName">=
        <span>{{fullName}}</span><br/>
        <button @click="changName()">改名卡</button>
    </div>

    <!-- 引入包-->
    <script src="https://cdn.jsdelivr.net/npm/vue@2.7.14/dist/vue.js"></script>
    <script>
        const app = new Vue({
            el: '#app',
            data: {
                firstName:'刘',
                lastName:'备',
            },
            methods:{
                changName(){
                    this.fullName='杨望'
                }
            },
            computed:{
                // fullName(){
                //    return this.firstName+this.lastName;
                // }
                fullName:{
                    get(){
                        return this.firstName+this.lastName;
                    },
                    set(value){
                        this.firstName=value.slice(0,1);
                        this.lastName=value.slice(1);
                    }
                }
            }
        })
    </script>
</body>

</html>